AO2 looks pretty cool, some SPCs like Metroid3 play now as well. However, there are some problems with SPC playback not seen in the previous AO:
-SPC effects are not played back correctly
-SPC tone heigt is not right for all instruments.
-Some instruments are way to loud at the start of an SPC, and then quickly the volume decreases. Very strange.
-Some SPCs still do not play correctly or at all, like Final Fantasy 2 (FF4).
[EDIT: Some additions]
-Volume of instruments fluctuating in some songs.
-Sometimes distorted sound
It seems that a nasty bug sneaked in[/EDIT]
I've also tried some gameboy stuff, witch plays back perfectly.
Richard, if you want I can send you SPCs that have clearly hearable problems. And of course thanks for this nice 2.0 version